As science progresses and sheds more light on our skin's physiological composition and function, we can use this knowledge to our benefit and care for our skin better than ever.
For example, today, we know the normal pH balance of the skin is fairly acidic, with values ranging from 4 to 5.5. We also know that most cleansing agents are alkaline and can disturb the skin's acid mantle. This information gives us insights into how we can use acids to help our skin restore its natural functions.
The most famously used acids in cosmetics are alpha hydroxy acids (AHA) group, which include glycolic acid, malic acid, citric acid, tartaric acid, and - of course - lactic acid. These acids' extensive application in cosmetics stems from the fact that AHAs have great bioavailability and can penetrate the skin easily.
In terms of popularity, glycolic acid reigns supreme, but lactic acid is a close second. Let's find out exactly what this acid is, how it's used in skincare, and what benefits to expect.
Let's begin.
What Exactly is Lactic Acid?
Lactic acid is an alpha-hydroxy acid (AHA) obtained through artificial synthesis and natural sources. You can derive lactic acid naturally from sour milk, fruit, vegetables, and other plants and dairy products. However, the lactic acid used in today's over-the-counter skincare products and treatments is usually synthetically produced.
Cosmetic products have this acid in their formulas for their exfoliating properties and anti-aging abilities. Additionally, lactic acid can make the skin softer and smoother, lighten age spots, stimulate cell and collagen renewal, and control the skin's natural moisture.
You can choose a topical OTC treatment, a professional treatment, or a stronger chemical peel with lactic acid. In fact, this is the hydroxy acid most frequently used for chemical peel products.
Even though glycolic acid is the main superstar, lactic is believed to be gentler on the skin, which is why it has a better reputation for sensitive skin types. It's also considered a starter acid, making it ideal for people who've never used acids on their skin before. It can be a wonderful alternative when stronger acids are out of the question.
How Does Lactic Acid Work?
Alpha hydroxy acids are water-soluble, or in other words, they love water molecules. Lactic acid specifically is extremely soluble - 1 part of lactic can dissolve 12 parts of water. This means lactic acid works by breaking down the bonds between cells holding the outer skin layer together. This way, when excess cell buildup on the skin is removed, there's an opportunity for newer, healthier-looking, smoother skin to be revealed below, leaving superficial imperfections in the past.
Besides helping the skin get rid of damaged skin cells, dirt, and cosmetic product residue, lactic acid stimulates collagen production and increases cell turnover, making the skin more elastic, tight, younger-looking, and able to heal from damage faster.
Although lactic is gentle, we're still talking about an acid with exfoliating properties, so you need to be careful - concentration intensity is key.
Different products use different concentrations of lactic in their formulas. The more concentrated the product is, the more intense the effect. You might feel a slight tingling sensation, which means it's working, but this shouldn't be painful and overly uncomfortable.
You'll probably have to experiment to find the best product for your skin. And there's always the possibility to mix lactic with other natural ingredients designed for a sensitive complexion. This will give you the benefits of lactic acid without causing skin irritation.
Benefits Of Using Lactic Acid for Skin
The legend says Cleopatra bathed in milk (which contains lactic acid) to get the glowing, white skin she's famous for.
You might not be Cleopatra, and you don't have to bathe in milk, but your skin surely deserves the best. Here are some of the benefits linked with using lactic acid.
Skin Hydration
Lactic acid, just like salicylic acid, is keratolytic. This means it increases moisture in the skin by softening and dissolving the keratin (a firm substance), holding the outermost layer of skin cells together. This helps the old skin cells fall off and stimulates the skin to retain more water.
Anti Aging Properties
Lactic acid is effective in reducing the symptoms of aging. So, don't be surprised if you see this acid in most anti-aging creams and serums.
Because of the way it works on the skin, it can:
Reduce Hyperpigmentation and Even Out Skin Tone
Some experts believe this acid is even more effective than glycolic acid in reducing dark spots and hyperpigmentation. This is because it removes the outermost damaged skin layer, allowing new and more even-looking skin to emerge on the surface.
Although the new skin cells aren't pigmented, they're more vulnerable to discoloration, so you need to protect the skin. Be careful not to expose the skin to sunlight since you can make things worse.
Stimulate Collagen Production
Our skin is a living organism that moves and stretches to fit our needs best. It usually goes back to its place, but time and external pollutants can make this process challenging. As we age, our skin loses collagen and becomes dry and saggy.
Collagen is key in keeping the skin elastic and youthful. Lactic acid stimulates collagen production, preventing your skin from becoming saggy and dull. Many wonderful products use ingredients like green tea and lemon extract to boost the tightening effect.
One word of caution, though - while they might be more effective, these products are usually harsher and should be avoided by people with skin sensitivity.
Smooth Fine Lines and Wrinkles
Another benefit of stimulating collagen production is it will reduce wrinkles and ensure fewer fine lines. Wrinkles are scar tissue that appears because the skin doesn't heal as effectively as it once did. The skin starts showing everyday "damage" from smiling, laughing, or frowning. This is because it becomes drier as we age. Stimulating collagen production regenerates the skin and helps it heal faster.
If you have sensitive or acne-prone skin and want to banish wrinkles, try the Wrinkle-Free All Day Moisturizer.
Shrinking Enlarged Pores
After genetics, the most common reason for enlarged pores is debris buildup. Alpha hydroxy acids can help reduce the appearance of enlarged pores by sweeping away dead skin cells, oil, and makeup residue that has built up on the skin's surface, keeping your pores clean and small.
Reducing Blemishes
When it comes to acne problems and blemishes, this acid is not as appreciated as salicylic acid, benzoyl peroxide or witch hazel, but it can help diminish the frequency of breakouts.
Lactic acid has anti-bacterial properties and prevents excess oil, debris, and dead cells from entering the pores. This can be beneficial for problematic and inflamed skin. It can treat acne by reducing the development of pimples and even aiding in healing acne breakouts faster.
Treating Keratosis Pilaris
Keratosis pilaris is a fancy name for the common "chicken skin" bumps that usually appear on the back of the arms. The rash can also appear on the thighs, cheeks, and buttocks.
Keratosis pilaris happens when a buildup of keratin clogs the pores, causing the bottom of the pore to enlarge. As a result, the skin gets irritated, and hair is often trapped in the pore. If you're in your teens, there's a good chance you already know what we're talking about, but be aware that keratosis pilaris can occur at any age.
Lactic acid breaks down the plug of cells that build up around the hair follicle, helps enlarged pores dissolve, and gets rid of excess keratin.
This is why it's no surprise that lactic acid is the key skincare ingredient in over-the-counter topical solutions for keratosis pilaris.
Side Effects of Lactic Acid for Skin
We mentioned that lactic is gentler than other AHAs, but remember - it's still powerful. Symptoms like redness, itching, burning, and peeling are not uncommon. They are even considered typical if you use an alpha-hydroxy acid for the first time.
If the intensity of the symptoms mentioned above are mild and go away on their own after an hour or two, there's no need to worry - you'll be okay.
In rare cases, when the symptoms persist for more than a few hours, or they're causing you great discomfort, you should consult with your doctor and avoid using lactic acid in the future.
Sun Damage and Sunscreen
Like all AHAs, this acid can make the skin more sensitive to sunlight, resulting in sun damage. This is one of the most important things you should remember before adding lactic acid to your skin care routine.
The dead skin cells on your face might irritate or clog your pores, but they'll protect new and vulnerable skin cells from damaging UV light. After treating the skin with lactic, dead skin cells are stripped away, and your skin is exposed.
Never leave the house without applying sunscreen. Experts recommend using SPF 30 or higher daily to combat sun exposure.
Remember that, for most lactic acid products, skin sensitivity can continue for about two weeks after you've stopped using it. Many people wish for a bronze tan, but you should be careful when your skin is vulnerable and overly sensitive. A nasty sunburn can bring you a lot of brown spots, wrinkles, and even scars.
Precautions
Many over-the-counter topical treatments for various skin conditions, like eczema, psoriasis, and rosacea, have lactic acid in their formulation.
Although this might indicate that lactic is relatively safe to apply when battling such conditions, some experts advise against it, as it can irritate the skin even further.
If you fall into this category, consult with your doctor or dermatologist before applying a lactic acid product. Other skincare products might suit you better.
How Different Products Use Lactic Acid
You can find this acid in many cosmetic products, from lactic acid peels to creams, lotions, masks, and cleansers.
For them to act on the skin and produce benefits, the final products should have a formula with a pH between 3 and 4. The typical concentration of lactic acid for over-the-counter products is between 5 and 12%.
Professional treatments and some chemical peels can have much higher concentrations. The higher the concentration, the stronger its effect on the skin - not only in terms of benefits but also in increasing the possibility of irritation and sensitivity.
The good news about lactic is that experts believe that skin sensitivity can be minimized or even eliminated if the formulation contains naturally soothing ingredients.
Nevertheless, remember that you shouldn't try pure and undiluted lactic acid because it's highly acidic and can lead to skin irritation and burns.
How to Use Lactic Acid in Your Daily Skincare Routine
Lactic acid skin care products can either exfoliate or hydrate the skin, depending on the formulation and concentration.
So, you can try lactic acid products like moisturizing creams and serums to smooth skin or use their exfoliating properties and go for a peel treatment.
Lactic Acid as a Moisturizer
Many products have lactic acid in low concentrations. If you find a product with low concentrations of lactic, you can definitely use it as a moisturizing agent for the skin. It's common for brands to have a lactic acid serum or moisturizer even when the formula doesn't exfoliate the skin.
Lactic acid will hydrate the skin because it's a humectant and reduces the trans-epidermal water loss through the increased production of oils and fats within the skin.
Go and check your moisturizer - maybe there's lactic in its formula. And if not, don't worry. There are plenty of other great active ingredients it can contain.
Lactic Acid as a Chemical Exfoliant
In higher concentrations, lactic acid is used as an AHA exfoliant in chemical peels. It works on the top layer of the skin by stimulating cell renewal, reducing pigmentation, and evening out skin tone. It can also improve skin texture and brighten the appearance of the face.
Because it's gentler on the skin than other AHAs, it's advertised for sensitive skin types.
You can also find this acid as an option in professional peels, which comes in extremely high concentrations. If you have sensitive skin but still want to try chemical exfoliants, a lactic acid treatment would be the best choice. Still, consult with your dermatologist before taking action.
Whether you need a product with a low lactic acid concentration or one with a higher concentration, get a high-quality formula enriched with antioxidants and vitamins that soothe and complement the effect of lactic acid on the skin.
Can Lactic Acid Be Used For All Skin Types?
Yes and no.
Yes, because lactic is the gentlest acid of the AHAs group and can be a wonderful alternative for people with easily irritated skin for whom glycolic acid is out of the question.
It works on oily and dry skin by encouraging the top layer to peel off, removing dead skin cells.
Additionally, this acid is known for regulating the skin's pH balance which can help the skin stay moisturized.
But, if you have extreme skin sensitivity, be careful. It's still an acidic ingredient that can cause mild irritation, redness, and burning sensations.
How to Use Lactic Acid on Different Skin Types
If you have an oily skin texture, use products with stronger lactic acid formulations that are meant to exfoliate the skin.
If you have dry or sensitive skin, find a product with low concentrations of lactic acid and use it as a moisturizer.
But if you don't fall into these categories and you're just facing some common skin problems, is it okay to use products with lactic acid? The answer is yes; lactic acid can help improve many skin imperfections.
If you're facing frequent acne breakouts, and have acne scars, wrinkles, fine lines, or brown spots and discoloration, choose a product with higher concentrations of this exfoliating acid.
Make sure to do a patch test first to see how your skin responds. Try the lactic acid product on a small but affected area to see if your skin reacts. The last thing we want to do is to irritate skin that's already inflamed. If you need more information on patch tests, check out this article.
Final Thoughts
Knowing more about the skin's physiology helps us understand how AHAs work. Today, lactic is widely used in cosmetic dermatology as a professional skin care treatment for various issues. It can be found in soured milk, fruits, and veg, but can also be made synthetically. Lactic acid can make the skin softer and smoother, reduce hyperpigmentation, stimulate collagen renewal, shrink pores, and make the skin appear tighter. Also, lactic acid speeds cell renewal.
It's gentler on sensitive skin compared to other AHAs, and it's usually recommended if you can't handle stronger acids.
But, there are some drawbacks. Lactic acid can also irritate the skin and cause sun sensitivity, so you should still be careful. Make sure to apply sunscreen often.
Depending on the concentration, lactic acid can nourish and moisturize the skin or help by exfoliating it. If it's your first time using lactic acid, it's best to start with a high-quality product with lots of vitamins and antioxidants and a low concentration of lactic acid. See how it goes from there.
References
Epidermal and dermal effects of topical lactic acid
Dual Effects of Alpha-Hydroxy Acids on the Skin
Lactic and lactobionic acids as typically moisturizing compounds
